Dual Monitor Arm (C-Clamp Desk Mount) smallest size available?

The smallest monitor arms I can find out there are those that can accommodate up to 2x 27" max monitors whereas I plan to use them on 2x 21" monitors which means the arms will be bent significantly at the "elbows" to have the 2 monitors together, and therefore require some space between the desk and the wall behind to accommodate this.

Anyone know of similar mounts which are sized for smaller screens (e.g. up to 2x 22" / 24" max) such that the arms are shorter and hence less bend at the "elbows" for use with my monitors?

Alternatively, are there any budget mounts with a flat horizontal bar (no "elbows") with the ability to slide the VESA clamps on either side along this horizontal bar? A higher cost example of such a mount is the Kensington space-saving arm for 2 monitors. Obviously this would restrict the screens to near the rear edge of the desk and a bit further away, but that's okay.

Thanks in advance!